Inner Core

The inner core is a nearly fully-solid metal ball at the center of the Earth. It is almost entirely made of solid iron and nickel. Though it may be mostly made of iron, and the temperature is extremely hot (hotter than the outer core of course) the iron does not melt. It's strange how the outer core is liquid but the inner core is solid! This is because of the pressure from the planet and that the iron is also mixed with other materials is what causes the iron to stay in a solid form.The depth of the inner core is between 5150 to 6370 kilometers. The inner core has a temperature estimated to about 10,800°F! The inner core is in the solid state of matter, whereas the outer core is in a liquid state of matter.